In the manufacturing processes of modem semiconductor devices, various materials and machines are manipulated to create a final product. Manufacturers have dedicated to reduce particulate contamination during processing so as to improve product yields. Due to the increasing complexity of semiconductor devices (e.g. many more layers and processes) and the development of larger wafers, the need for defect detection and control is further emphasized.
The inspection on the semi-manufactured product is frequently performed during manufacture by using wafer scanner in order to timely find the defects. The wafer scanner may detect the defects, analyze the defects to identify the types of the defects, and locate the defects on the wafer, so as to assist the operator in evaluating and correcting the manufacturing processes that cause the defects.
However, since there are hundreds of processes in manufacturing the product, the possible factors that cause the defects are considerable and the origin of the defect is hard to derive. As a result, the evaluation of defects highly relies on human knowledge and expertise and costs a large amount of time and efforts, but the result is usually not satisfactory.